Docs: Clarify transformation functions reference docs (#46903)

* Docs: Remove 'Reference' prefix from all reference topic filenames: Per issue #46818, prefixing reference topics with "Reference" can damage usability. Remove the prefix from filenames.

* Docs: Remove "Reference:" prefix from titles and ToC headings: Per issue #46818, prefixing reference topics with "Reference" can damage usability. Remove the prefix from titles and ToC headings. H1s retain the prefix to emphasize the nature of the doc without affecting the docs' discoverability.

* Docs: Move Transformation functions reference alongside Transformation docs
* Docs: Update links to reference docs in Transformation docs
* Docs: Update links to reference docs in Panels docs
* Docs: Update links to query options reference across docs
* Docs: Update links to standard field definitions reference across docs
* Docs: Update links to calculation types reference across docs
* Docs: Update links to transformation functions reference across docs
* Docs: Rename apply transformation doc filename to add transformation
* Docs: Rename apply transformation doc to add transformation
* Docs: Update links to add transformation doc across docs
* Docs: Update relrefs in Transformation functions reference

docs/sources/whatsnew/whats-new-in-v7-0.md

@@ -58,7 +58,7 @@ In the future we will add more workflows and integrations so that correlating be
 
 The data you want to visualize can come from many different places and it is usually not in exactly the right form. Users can now transform non-time series data into tables (e.g., JSON files or even simple lookup tables) in seconds without any customization or additional overhead. They can then combine non-time series data with any other data in Grafana; data from an external database or a panel that already exists in one of their current dashboards.
 
-By chaining a simple set of point and click [transformations]({{< relref "../panels/reference-transformation-functions.md" >}}), users will be able join, pivot, filter, re-name and do calculations to get the results they need. Perfect for operations across queries or data sources missing essential data transformations.
+By chaining a simple set of point and click [transformations]({{< relref "../panels/transform-data/transformation-functions.md" >}}), users will be able join, pivot, filter, re-name and do calculations to get the results they need. Perfect for operations across queries or data sources missing essential data transformations.
 
 [Transformations]({{< relref "../panels/transform-data/about-transformation.md" >}}) also adds the ability to do math across queries. Lots of data sources do not support this natively, so being able to do it in Grafana is a powerful feature.
 
@@ -78,7 +78,7 @@ We are also introducing a new shared data model for both time series and table d
 - **Outer join:** Joins many time series/tables by a field. This can be used to outer join multiple time series on the _time_ field to show many time series in one table.
 - **Add field from calculation:** This is a powerful transformation that allows you perform many different types of math operations and add the result as a new field. Can be used to calculate the difference between two series or fields and add the result to a new field. Or multiply one field with another and add the result to a new field.
 
-Learn more about this feature in [Transformations]({{< relref "../panels/reference-transformation-functions.md" >}}).
+Learn more about this feature in [Transformations]({{< relref "../panels/transform-data/transformation-functions.md" >}}).
 
 ## Field options and overrides
 

docs/sources/whatsnew/whats-new-in-v7-2.md

@@ -77,8 +77,8 @@ You can now add override rules that use a regex matcher to choose which fields t
 
 Grafana 7.2 includes the following transformation enhancements:
 
-- A new [Group By]({{< relref "../panels/reference-transformation-functions.md#group-by">}}) transformation that allows you to group by multiple fields and add any number of aggregations for other fields.
-- The [Labels to fields]({{< relref "../panels/reference-transformation-functions.md#labels-to-fields">}}) transformation now allows you to pick one label and use that as the name of the value field.
+- A new [Group By]({{< relref "../panels/transform-data/transformation-functions.md#group-by">}}) transformation that allows you to group by multiple fields and add any number of aggregations for other fields.
+- The [Labels to fields]({{< relref "../panels/transform-data/transformation-functions.md#labels-to-fields">}}) transformation now allows you to pick one label and use that as the name of the value field.
 - You can drag transformations to reorder them. Remember that transformations are processed in the order they are listed in the UI, so think before you move something!
 
 {{< figure src="/static/img/docs/v72/transformations.gif" max-width="800px" caption="Group by and reordering of transformations" >}}

docs/sources/whatsnew/whats-new-in-v7-4.md

@@ -54,7 +54,7 @@ The following transformations were added in Grafana 7.4.
 
 The _Sort by_ transformation allows you to sort data before sending it to the visualization.
 
-For more information, refer to [Sort by]({{< relref "../panels/reference-transformation-functions.md#sort-by" >}}).
+For more information, refer to [Sort by]({{< relref "../panels/transform-data/transformation-functions.md#sort-by" >}}).
 
 #### Filter data by value transform
 
@@ -62,7 +62,7 @@ The new _Filter data by value_ transformation allows you to filter your data dir
 
 This transformation is very useful if your data source does not natively filter by values. You might also use this to narrow values to display if you are using a shared query.
 
-For more information, refer to [Filter data by value]({{< relref "../panels/reference-transformation-functions.md#filter-data-by-value" >}}).
+For more information, refer to [Filter data by value]({{< relref "../panels/transform-data/transformation-functions.md#filter-data-by-value" >}}).
 
 ### New override option
 

docs/sources/whatsnew/whats-new-in-v8-1.md

@@ -53,7 +53,7 @@ Grafana 8.1 includes some significant enhancements to transformations, including
 
 #### Config from query (Beta)
 
-This transformation enables panel config (Threshold, Min, Max, etc.) to be derived from query results. For more information, refer to [Config from query results]({{< relref "../panels/reference-transformation-functions.md#config-from-query-results" >}}).
+This transformation enables panel config (Threshold, Min, Max, etc.) to be derived from query results. For more information, refer to [Config from query results]({{< relref "../panels/transform-data/transformation-functions.md#config-from-query-results" >}}).
 
 #### Rows to fields (Beta)
 
@@ -75,7 +75,7 @@ Output:
 
 As you can see each row in the source data becomes a separate field. Each field now also has a max config option set. Options like **Min**, **Max**, **Unit** and **Thresholds** are all part of field configuration and if set like this will be used by the visualization instead of any options manually configured in the panel editor options pane.
 
-For more on how to use this transformation, refer to [Rows to fields transform]({{< relref "../panels/reference-transformation-functions.md#rows-to-fields" >}}).
+For more on how to use this transformation, refer to [Rows to fields transform]({{< relref "../panels/transform-data/transformation-functions.md#rows-to-fields" >}}).
 
 #### Contextual & Inline Help